Electrical connector socket



June 15, 1954 J |NN 2,681,441

ELECTRICAL CONNECTOR SOCKET Filed May 17, 1952 Iii/ 200a)! 1 11 '0 JEQOME 5. ZY/v/v,

INVENTOR.

Patented June 15, 1954 ELECTRICAL CONNECTOR SOCKET Jerome S. Linn, Los Angeles, Calif., assignor to Elcon Mfg. 00., Los Angeles, Calif., a corporation of California Application May 17, 1952, Serial No. 288,416

14 Claims. (Cl. 339-259) This invention relates to improved electrical connectors of a type comprising a tubular open ended electrically conductive socket into WhlCh a mating conductive pin is to be inserted.

The general object of the present invention is to provide a socket connector which is so con structed as to assure, upon each insertion of a mating pin, a more positive and effective electrical connection with the pin than has been achieved by prior pin and socket connectors. Particularly contemplated is a socket structure so designed as to assure direct electrical contact with the pin at a large number of dilferent points,

so that the overall resistance of the connector assembly is very low, and the heat loss in the connection is therefore at a minimum. At the same time, it is an object of the invention to so form the socket as to facilitate the dissipation of Whatever small amount of heat may be formed in the connection at very high loads.

Further features of the invention have to do with the formation of the present sockets in a manner making possible considerably lower mating pin insertion and pull out forces than are normally required for sockets of the same size, as

pin, it has been found highly desirable that the individual elements be of essentially helical formation. Also, to maintain effective contact between the elements and pin regardless of slight twisting or deformation of the individual elemerits, I preferably form the elements of circular cross-section wire. The wire elements may be mounted at first ends thereof to a suitable base or carrier body, and have second ends at the open end of the socket which are free for relative radially expanding movement upon insertion of a pin into the socket. The base may include an electrically conductive portion by which the socket is electrically connected to an associated lead.

For maintaining the various socket forming wires or elements in tight electrical contact with a received pin, the socket preferably includes one or more annular spring units extending about the wires or elements and yieldingly urging them radially inwardly against the pin. These spring units may be positioned axially of the socket by partial reception within an annular series of notches formed in the outer surfaces of the elongated elements.

For assuring a most uniform inward force against the elements in a structurally very simple arrangement, the spring units may comprise coil springs, the individual turns of which ex tend entirely about all of the elements. In order that such a coil spring may be radially expansible to the degree desired upon insertion of a mating pin, each spring should be so formed as to normally tend to return to a condition in which its adjacent turns are spaced axially apart. The spring may then be radially expanded upon insertion of a pin, without having to overcome the frictional resistance to expansion which would be present if adjacent turns of the spring were normally urged tightly together. Also, some radial expansion of the socket is permitted by virtue merely of the axial contraction of the spring, that is, as its successive turns move more closely together. With further regard to the spring structure, it has been found highly desirable that the ends of the coil spring be distorted slightly radially outwardly into a spaced relation with the socket forming wires or elements, to prevent the spring ends from digging into or catching on the elements.

Radially inward deflection of the wires or elongated elements may be resisted or limited by a member which is inserted into the socket and engaged by the elements at a location inwardly beyond the pin-receiving portion of the socket. This member may be of an electrically conductive material, and electrically engage the elements or wires to assist in the transmission of current through the inner portion of the socket and thus reduce the resistance to current flow. Best re sults are achieved when this member is solid and externally cylindrical, with its upper end immediately below the contact area.

Additional features of the invention have to do with a special formation of the outer free ends of the socket forming wires or elements to present a smooth entrance end to a pin and to provide an interlock between the outer endsof the elements, which interlock assures sufiicient mechanical resistance to deformation of both the individual elements and socket. For achievand be received radially outwardlyof anadjacent element, to thus limit the relative radially f outward movement of that element. In order that some relative movement oi'the-element-ends may be permitted, to enable conformance of the socket to slightly irregularipins, the overlapping end portion of each element-is spaced a short distance radially outwardly from the overlapped portion of the adjacent element. I,

The above and other features andv objects of the present invention will be better t nderstocd from the following detailed description of the 1? typical'enibodiments illustrated in the "accompanyi'ng drawing, in which:

Fig.1 is'a perspective'view of a first form of 5 electrical socket embodying the invention;

Fig. 2 iSanenlargedside view ofthe Fig. 1 socket, shown partly in section;

Figs; 3,4 an'd'5are sectional'v'iews taken on lines 3 3, i"4, and Ea E, respectively, of Fig. 2; and

Fig. G'isa side -view, partly broken away, of a'se'c'ond form of the invention.

The'socket lflshown in Figs. l-'5 comprises 'a basemeinber i I, a plurality of elongated circular cross'se'ction"socket forming wires l2 carneuin circular arrangement-by the base member, I "an inner backing'plug '53 at the inside of the socket/and a plurality of springs l4 constricting "the 'wires toward'both the'plug' i3 and a contact "pine: with which the socket mates. The base inernbers H,"wires l2, and'plug l3 are-all'formed 1 of 'a suitable electrically conductive material, "preferably coppen'andtheentire socket may be "coveredwit'h'a thin plate'of silverto assure'the maintenance of y a good electrically conductive surface. Base member H may be'sha-ped as 'iorrr'ied and contain a pair of openings [5 and 16, for receiving-respectively a mountingscrew i! by which" the socket is attachable to a support I8,--and a terminal lB-to be electrically connected to a lead28 "Wires i2are mounted in'a circular arrangement to the base-member l i, typically by reception of their base ends 21 withina circular opening 22 in the base. Acircularplug 23'rnaybe received-within" base opening '22 and at-the in- .1 9 5m of wires 52, to form with the base an annularspace'within which the ends 2! of the "wires "are" received and retained. An electrically condiict'ive' solder-24 may-be injected into the space "between plug-2 and. the base member and about the wires-to integrate the base portions of the wires and the parts engaged thereby into an electrically conductive'unit. I I v The base portions 21- of wires l2, that is, the

portions of the wires secured. within the opening of'base member ll, preferably extend parallel and in the direction of the axis of the socket. The portions 26* of the wires outwardly-beyond the ease member are given a helical twist, which continues to the outer free relatively'movable "erids 2'a' 'of the "wires. 'The'wires' are formed of "a niaterial which is'sufficiently'flexible to assure radial deflection of the wires in conformance with the mating contact pin 3 l The outer ends 25 of the wires areinterlocked in a manner limiting the relative radial deflection of adjacent wires. For this purpose, the end 25 of each wire is turned radially outwardly and then doubled back angularly as shown to a location overlapping and received radially outwardly of an adjacent wire. Radially outward deflection of each wire relative to the adjacent "wire is thus limitedfbyerigag'ement with the turned end or that adjacent wire. I In certain instances, it is desirable, for most efiective control of the relative movement of the wires; thateach wire end 25 overlap two adjacent wires as shown. It is also noted that, in order to perinit sdmerelative movement of the wires,

' the turned'erid portion 25 of each wire is normally (1. "e. when the wires are in an exactly -circu1ararrangement) spaced radially outwardly from the wire which it overiaps, so that the over-lapped wire may move outwardly a predetermined distance befdre its relative movement 'islimited. To attain such a spaced relation of the wires and wire' ends, the wires are turned 'back in such-a manner that the inner wireengaging surface of the end'25 of a'particular wire is located farther from the socket axis than isthe portionoi the outer surface of that same wire'which is to' beengagedby the turned end of'an adjacent wire. It is also pointed out that the manner in which the ivire ends 25 are curved outwardly and thenback is' such as to form a smoothly converging pinreceiving throat at the open end of the socketJ The inner backing plug i3 preferably is elon gated as shown,and has an'outer 'eSsentiaIly cylindrical surface'engaging wires it along substantially the entire extent of the plug. The plug is solid to positively limit inward deflection of the engaged wireportions and to afford a Wide cross-section electrical path at'the base of the socket. Plug it" engages the wire mounting plug 23 at its inner end, and terminates outwardly at an end'30, which is-axially spaced from the outer ends 25 of the wires a distance permitting reception of the pin 3 l within the socket.

' Plug I3 is not directly attached to any other formed i-n'the'outersurfaes'of the wires.

part of the socket, to thus permit movement of the plug in a manner allowingsome change of the socket axis relative to base ll.

Each cf the springs ls comprises-a coil spring,

the individual turns of which extend entirely about the socket formed by wires'l2. Eachspring is positioned relative to the wires by partial reception within' a circular series'of notches 32 A number of such springs inay beemployed at locations spaced-axially along thesocket, to urge'the wiresinwardly against andinto tightelectrical contact withboth plug-'29 and pin 3 l. Preferably, iour' springs are-employed,*t'wo being received aboutthe pin receiving portion" of'the socket,

and two about the plug 1 3.

The-springs are So formed that their individual turnsnorrnally tend to return to the condition of Fig. 2, in which they are slightlyaxially spaced to-thus prevent excessive'resistance to expansion resulting from tight frictional contact between the 'turns. -Such" spacirig' also' facilitates' radial expansion of the spring, since some expansion is then allowed by mere axial contraction of the spring. It'isfurther noted that the'ends 3311f the individual springs (see Fig.4) are distorted slightly outwardly-in radially spaced relation to the wires -|2,-to preventthe spring ends from digging into or catching on the wires. Preferably,

each-spring-comprises morethan 1 and less than 2 turns about the socket. It is found desirable for best operation that only one turn of each spring M be received within the correspond ing positioning notches or recesses 32, and that the notches be so dimensioned as to allow freedom of movement of the received turns. These purposes are preferably achieved by giving the notches a width axially of the socket equal to about 1 times the diameter of the spring wire.

In placing the socket of Figs. 1 to 5 in use, the socket is first of all mounted to support l8, and terminal 19 is then electrically connected to lead 20. A mating contact pin 3| may then be inserted into the end of the socket to the position of Fig. 2, to form an effective but releasable electrical connection between the pin and socket. The wires, by virtue of their helical formation and the manner in which they are urged tightly inwardly against the pin, form a large number of positive electrical connections between the pin and socket to in the aggregate produce a connection of very low resistance with the pin. Plug 32 gives rigidity to the socket and decreases its electrical resistance, and at the same time does not interfere with conformance of the wires to the pin, since the plug is not in any way directly attached to the wires. The turned ends 25 of the wires form an effective interlock between the elements, but still permit their relative movement in conforming to a pin.

To assure proper movability of the wires, the helical twist of the wires should extend through at least about 180 circular degrees from the base of the socket to the outer free ends of the wires. Also, in order that the wires will not unduly resist radial expansion, it is desirable that the helical twist of the wires be not greater than about 360 circular degrees from the pin engaging portion of the socket, i. e. from the end 30 of plug $3, to the free ends 25 of the wires.

Fig. 6 shows a variational form of the invention which takes the form of a line connector having at its opposite ends two socket recesses for receiving a pair of pins which are to be electrically connected together. constructed in basically the same manner as the Figs. 1 to 5 form of the invention, including a number of circularly arranged helical wires I2o. These wires are secured in the illustrated circular arrangement by reception of their central portions within a tubular sleeve 1 la, against which the wires are retained by an inner copper plug 23a. As in the first form of the invention, the wires may be integrated with the members Ha and 23a between which they are received by electrically conductive soldering material 24a. At opposite ends of sleeve Ila and plug 23a, the

wires receive a pair of backing plugs l3a. The

wires are yieldingly urged radially inwardly against mating pins 3| and plugs 13a by a number of springs Ma received within positioning notches in the wires. The outer ends 25a of the wires are turned back into interlocking relation in the same manner as ends 25 of the Figs. 1 to 5 form of socket.

I claim:

1. An electrical connector comprising a plurality of elongated electrically conductive elements mounted in an essentially circular arrangement and extending essentially helically in a common general direction to form together an essentially tubular open ended pin-receiving socket, said elements being defiectible radially of said socket, and a coil spring having an individual turn thereof completely encircling said helical This connector is 6 elements and urging them radially inwardly against a received pin, said spring having ends normally distorted radially outwardly into radially spaced relation to said elements.

2. An electrical connector comprising a base body having an electrically conductive portion, a plurality of elongated substantially circular cross section electrically conductive wires mounted to said body and projecting therefrom helically in a common general direction to form together an essentially tubular open ended pin receiving socket, said wires being deflectible radially of said socket in conformance to a received pin, said wires having notches formed in the outer surfaces thereof along a plurality of axially spaced areas each extending circularly about the socket, a solid electrically conductive axially elongated essentially cylindrical member inserted in said socket in electrical contact with the wires at a location. near said base and acting to limit radially inward movement of the Wires at said location, said member terminating at a location spaced from said open end of the socket to permit reception of a pin within the socket beyond the member, and a plurality of coil springs extending about said wires at axially spaced locations and partially received. within said notches, the individual turns of said springs encircling said wires and urging them radially inwardly against said member and a received pin, each of said individual wires being doubled back angularly at said open end of the socket to a position of extension across the path of radially outward deflection of an adjacent wire. 7

3. An electrical connector comprising a plurality of elongated electrically conductive ele ments in an essentially circular arrangement forming together an essentially tubular socket having an open end for receiving a mating electrically conductive pin, said elements being defiectible radially of said socket, and individual ones of said elements having portions extending to positions in the paths of radially outward movement of adjacent elements to thereby restrict relative movement of the elements.

4. An electrical connector as recited in claim 3, in which said portions of the elements are located at said open end of the socket, said connector including spring means extending about said helical elements for urging them radially inwardly against a pin received in the socket.

5. An electrical connector comprising a plurality of elongated electrically conductive elements in an essentially circular arrangement extending essentially helically in a common general direction and forming together an essentially tubular socket having an open end for receiving a mating electrically conductive pin, said elements being deflectible radially of said socket, and individual ones of said elements having portions extending to positions in the paths of radially outward movement of adjacent elements to restrict relative movement of the elements.

6. An electrical connector as recited in claim 5 in which said portions of the elements comprise ends thereof at said open end of the socket turned radially outwardly and to said positions in the paths of radially outward movement of adjacent elements.

'7. An electrical connector as recited in claim 5 in which said portions of the elements comprise ends thereof received in side-by-side relation about said open end of the socket and each turned radially outwardly and then doubled back analyser "ins anzaxial'ilirection-awayirom said: socket ten'd at ananglesu'chvastozhave extent circularly aboutzthe socket axis Iand to :extend 1-a'cross -'.-the path of radially outward-movement of 'anadjacent element.

8JAn :electrical'connector as recited in claim -7 iin-"Which said elementsicomprisewires' of substantially circular cross section, saidend of each ofrs'aid Wires extending across the path of radially outward movement of two adjacent wires :and being radially spaced from one of said wires.

- 9.1An-r'felectrical connector comprising a body -havi-ngan electrically conductive portion, a plurality -obelongated-electrically conductive eele- 'm'ents'lfixed'at first ends to said bodyand pro- 1 "jecting'therefrom in accircular arrangement and essentially helically to'form together-an essentially-tubular sockethafing-an open end forre- ;ceiving--a mating electrically conductive pin, said elements being deflectiblesradially of said socket,

spring Jmeans-disposedaboflt said helical ele- -ments and urging them radially inwardly against ai -pin when'receivedin the socket, the individual elements havingsecond end portionsat said open endiof the socket extending topositions in the 'paths; of radially outward movement of adjacent receivinga mating electrically conductive pin, said elements beingclefieotible radially oi said socket; spring means extending about said helical elementsxand urging them radially 'inwardlyiand Hag'ainst: ajpin wh'enfreceived in=said socket, and

an electrically conductive: circular plug? received within said'socket-at a location spaced: flOiTFSaid 'open'end' of thesoclzet'and limiting radially inward movement of the: elements atsaid location, said plughaving an axial extent as" great as its transverse-"extent, said elements having portions extending alongside and electrically engaging saidrnember and movable relativethereto.

ll. An electrical connector as'recited in claim 10, includingan electrically: conductivebody carrying said electrically conductive selernentafand -means attaching saidelements to saidtbodyin an essentially circular arrangement and intfixed ielation-thereto -atpoint beyond i said iplug in -a fdirectiorrawayr from 'SfizldTOlGBIliElIdiOfili-hfilsflflell, said-elements comprising-.2, plurality of swiresiof essentially circular :cross section; said :outerrsurface of said plugibeingi substantially;cylindrical, ,a'ndsaid'spring means including :a firsuspring disposed about the-wires atsa location radially oppositeisaid'plug, and a second springrdisposed about the Wires beyond saidxplug in a. direction .toward'said open end of the socket.

12.. An electrical connector comprising a zpluvrality. of r elongated electrically conductive elements mounted in an essentially=circular ar .:rangement and extendingtessentially helically in acommon general direction and forming-together at their opposite ends a pair LOf cssentially tubu- .lar oppositely facing sockets for receiving mating :electrically conductive pins, said elements having :portions adjacent their opposite'endsrespectively forming said sockets and deflectibleradially of said sockets, and spring means extending about said elements and-urging said opposite end-portionsra'dially inwardlyand against mating pi-ns when received in the sockets, the individualv helical elements having at both of their-ends portions 7 turned to positions in the paths oi radially-outward movement ofadjacent elements to thereby restrict relative movement of the elements.

.13. An electrical connectoras'recited-in elairn 12, in which each end of eachelement is doubled back toward the opposite end of that 'elernent and at an angle such-as to have extent circularly about the socket axis.

i l. An electrical connector-as recited in claim -12, including means securing-said--elements-t0- gether in said circular arrangement-at a location intermediate their oppositeends.

'References Citediin' thefi'le ofthis-patent UNITED STATES PATENTS Number Name Date 839,260 Benson Dec. 25, 1906 2,273,069 Rossman Feb. 17,1942 2,363,295 Cotter Nov. 21, 1944 .-2,393,083 Wisegarver Jan. 15, 1946 r 2,427,001 Hubbell et al M Septhle-i'l FOREIGN PATENTS Number Country .Date

. 291,190 Great Britain May 31, 1928 1433,622 .Great Britain Augrl9, 1935 520,028 .GreatBritain Apr. 12,1940 811,272 France Jan. 14, 1937 

